Non-diffusing coupling agents can be introduced into the photographic layers containing them either in aqueous alkaline solution (in this case at least one acid solubilizing group of the SO.sub.3 H or COOH type must be present in the coupling agent molecule), or dissolved in a high boiling solvent dispersed in the spreading composition of the layer. Briefly, this second method, which is preferred for the purposes of the present invention, is known as the "dispersion method", and substantially consists firstly of dissolving the coupling agent in a water-immiscible organic solvent, and then dispersing the solution thus obtained as extremely fine droplets in the gelatin (a description of the dispersion method is given in U.S. Pat. Nos. 2,322,207, 2,801,170, 2,801,171 and 2,991,177).
The mechanical properties of the photographic material depend on those of their constituent layers. Even in the presence of a good support, properties can be comprised by the poor characteristics of the other layers. In this respect, the mechanical properties of the gelatin layers of the aforesaid photographic elements, for example, their elasticity, fragility and flatness, depend largely on climatic conditions. In, for example, low humidity and temperature conditions, if the gelatin layers are subjected to bending, they break and this breakage is transmitted from one layer to another until it reaches the support, to also damage this layer.